1. Feature of the Week: μOCT Imaging Using Depth of Focus Extension by Self-Imaging Wavefront Division in a Common-Path Fiber Optic Probe

    Optical coherence tomography (OCT) is an attractive medical modality due to its ability to acquire high-resolution, cross-sectional images inside the body using flexible, small-diameter, scanning fiber optic probes. Conventional, cross-sectional OCT imaging technologies have approximately 10-μm axial resolution and 30-μm lateral resolution, specifications that enable the visualization of microscopic architectural morphology. While this resolution is useful for many clinical applications, it is insufficient for resolving individual cells that characterize many diseases. To address this gap, a supercontinuum-laser-based, μm-resolution OCT (μOCT) system and a 500 μm-diameter, extended depth of focus single fiber optic probe for endoscopic and intravascular imaging were designed and fabricated. At the distal tip of the fiber optic probe, a cylindrical waveguide was used to divide the wavefront to provide multiple circular propagation modes. Once transmitted through a relatively high NA lens (NA >0.1), these modes were projected as multiple coaxial foci (~3 μm full width at half maximum (FWHM)) over a greatly extended focal depth range. The distal tip of the probe also contained a common-path reference reflectance to minimize polarization and dispersion imbalances between sample and reference arm light. Measurements showed that the probe provides a 20-fold depth of focus extension, maintaining a 3-5 µm lateral resolution (FWHM of PSF) and a 2 μm axial resolution over a depth range of approximately 1 mm. These results suggest that this new optical configuration will be useful for achieving high-resolution, cross-sectional OCT imaging in catheter/endoscope-based medical imaging devices.

    For more information see recent Article. Courtesy Biwei Yin from Massachusetts General Hospital. To share this article click Here.
  2. Recent Articles From Around The Web

    1. IEEE Boston Photonics Society Talk on Swept Source Lasers by Bart Johnson

      IEEE Boston Photonics Society Talk on Swept Source Lasers by Bart Johnson

      The development of swept source lasers has made high-speed optical coherence tomography (OCT) cost effective at 1060 and 1310 nm wavelengths. Axsun Technologies manufactures this type of source and has made inroads into ophthalmology and cardiology applications. The 1060 product, for example, tunes 990-1100 nm at a 100 kHz sweep rate. This external cavity diode laser is tuned by a MEMS Fabry-Perot filter. The act of rapidly sweeping the filter induces a mode-locking behavior. This is because when the pulses deplete the gain medium they are red shifted due to the index rise in the semiconductor optical amplifier associated with ...

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    2. Author Response: Quantification of Vessel Density in Retinal Optical Coherence Tomography Angiography Images Using Local Fractal Dimension

      Author Response: Quantification of Vessel Density in Retinal Optical Coherence Tomography Angiography Images Using Local Fractal Dimension

      On behalf of the author team, we thank Hu and Ding 1 for noting our study 2 to be interesting. Hu and Ding raise pertinent questions related to reproducibility of the optical coherence tomography angiography (OCTA) images and intra- and interobserver variability. We do acknowledge that the OCTA examination can take a long time, and patient eye movement can be a confounder in any analyses. There are two issues to be considered. One is the reproducibility of the OCTA image and the other is the reproducibility of the local fractal dimension method. In the latter case, as long as the ...

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    3. Quantification of Vessel Density in Retinal Optical Coherence Tomography Angiography Images Using Local Fractal Dimension

      Quantification of Vessel Density in Retinal Optical Coherence Tomography Angiography Images Using Local Fractal Dimension

      We read with interest the article by Gadde and colleagues 1 on quantifying vessel density and the foveal avascular zone (FAZ) area in optical coherence tomography angiography (OCTA) images using a fully automated local fractal dimension method. The authors concluded that this novel method can calculate retinal vessel density and the FAZ area. They also contended that retinal vessel density was not correlated with age and that the inferior zone of retinal vessel density is largest in the parafoveal region. We congratulate and applaud their interesting and important work on this topic; however, we have one question for the authors ...

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      Mentions: Optovue
    4. LONG-TERM RETROSPECTIVE ANALYSIS OF VISUAL ACUITY AND OPTICAL COHERENCE TOPOGRAPHIC CHANGES AFTER SINGLE VERSUS DOUBLE PEELING DURING VITRECTOMY FOR MACULAR EPIRETINAL MEMBRANES

      LONG-TERM RETROSPECTIVE ANALYSIS OF VISUAL ACUITY AND OPTICAL COHERENCE TOPOGRAPHIC CHANGES AFTER SINGLE VERSUS DOUBLE PEELING DURING VITRECTOMY FOR MACULAR EPIRETINAL MEMBRANES

      Purpose: To determine the long-term effect of internal limiting membrane with associated epiretinal membrane (ERM) peeling versus single peeling alone in terms of best-corrected visual acuity and anatomical outcomes on spectral-domain optical coherence tomography. Methods: This retrospective comparative cohort study of patients who had follow-up of >1 year and underwent surgery for ERM by a single surgeon (S.C.) from January 1, 2008 to December 31, 2012 compared cases in which the internal limiting membrane was stained with brilliant blue G to facilitate double peeling (n = 42) and single peeling (n = 43) of the ERM alone for up to 3 ...

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    5. Calibration Phantoms for Optical Coherence Tomography at Aston University

      Calibration Phantoms for Optical Coherence Tomography at Aston University

      Calibration Phantoms for Optical Coherence Tomography Applications are invited for a three year Postgraduate studentship, supported by the School of Engineering and Applied Science, to be undertaken within the Aston Institute of Photonic Technologies at Aston University. The successful applicant will join an established experimental group working on the design and fabrication of calibration phantoms for optical coherence tomography using femtosecond laser materials processing. The studentship is offered in collaboration with Arden Photonics . The position is available to start in October 2016 (subject to negotiation) Financial Support This studentship includes a fee bursary to cover the home/EU fees rate ...

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    6. Nondestructive analysis of automotive paints with spectral domain optical coherence tomography

      Nondestructive analysis of automotive paints with spectral domain optical coherence tomography

      We have demonstrated for the first time, to our knowledge, the use of optical coherence tomography (OCT) as an analytical tool for nondestructively characterizing the individual paint layer thickness of multiple layered automotive paints. A graph-based segmentation method was used for automatic analysis of the thickness distribution for the top layers of solid color paints. The thicknesses measured with OCT were in good agreement with the optical microscope and ultrasonic techniques that are the current standard in the automobile industry. Because of its high axial resolution (5.5 μm), the OCT technique was shown to be able to resolve the ...

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      Mentions: Yalin Zheng
    7. SS-OCT PCIe Card from Keysight Technologies

      SS-OCT PCIe Card from Keysight Technologies

      Keysight Technologies Inc. offers swept source optical coherence tomography (SS-OCT) application options for the U5303A compact, dual-channel ADC card, delivering high dynamic range and a high effective number of bits for enhanced image quality. The new options support up to 1 GS/s on the 12-bit, high-speed data acquisition peripheral component interconnect express (PCIe) card. Image acquisition is featured at a rate of 200 kHz, continuously. The real-time processing solution allows OEMs to develop SS-OCT engines using the development environment provided, which includes a graphical user interface and C++ programming language. The new options also ensure improved spurious-free dynamic range ...

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    8. Vessel-contrast enhancement in label-free optical coherence angiography based on phase and amplitude speckle variability

      Vessel-contrast enhancement in label-free optical coherence angiography based on phase and amplitude speckle variability

      Recently proposed in vivo label-free optical coherence angiography techniques based on phase and amplitude speckle variability often require additional signal pre- and post processing operations to enhance vessel-contrast. We observe here 1) contrast enhancement by optimizing the signal normalization/weighing before processing; 2) algorithm based on Kasai estimator for phase compensation between processed A-scans to reduce masking role of motion artifacts; and 3) image projection through the imaging depth for en face plotting. We demonstrate the efficiency of proposed additional algorithms as for the microcirculation imaging of hamsters cheek in vivo as for the preliminary microcirculation imaging of patients after ...

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    9. Optical coherence tomography angiography in pediatric choroidal neovascularization

      Optical coherence tomography angiography in pediatric choroidal neovascularization

      Purpose : To report two cases of pediatric choroidal neovascularization (CNV) and the associated neovascular and retinal findings identified on Optical Coherence Tomography Angiography (OCTA) imaging. Methods : A 14-year-old boy with handheld laser-induced maculopathy-related CNV and a 13-year-old boy with idiopathic CNV were evaluated with visual acuity testing, slit-lamp exam, fundus photography, fluorescein angiography, indocyanine green angiography, spectral domain optical coherence tomography, and OCTA. Results : Macular CNV were identified in both pediatric patients using OCTA imaging. The first case demonstrated a classic pediatric type II CNV with a "tree-like" pattern and a single vessel in-growth site, while the second case demonstrated ...

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    10. Improved vascular healing after successful treatment of very late sirolimus-eluting stent thrombosis with a bare metal stent implantation - A serial optical coherence tomography study

      Improved vascular healing after successful treatment of very late sirolimus-eluting stent thrombosis with a bare metal stent implantation - A serial optical coherence tomography study

      We present a case of a patient with non-ST-elevation myocardial infarction due to very late stent thrombosis, 2 years after a sirolimus-eluting stent implantation (SES). Optical coherence tomography (OCT) imaging identified vessel wall destruction of the whole stented coronary segment with multiple cavity formations along the entire stent length, severe struts malapposition and thrombi. The patient was treated successfully with the implantation of a bare metal stent (BMS). Follow-up OCT imaging at 12 months revealed improvement of vascular healing with complete re-endothelialization of the distal parts of the new BMS, while the stent body remained partly uncover suggesting vascular toxicity ...

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    11. Macular disease detection with a swept-source optical coherence tomography-based biometry device in patients scheduled for cataract surgery

      Macular disease detection with a swept-source optical coherence tomography-based biometry device in patients scheduled for cataract surgery

      Purpose To assess the sensitivity and specificity for detecting macular disease with a new optical biometry device with swept-source optical coherence tomography (SS-OCT) used before cataract surgery. Setting Hanusch Hospital, Vienna, Austria. Design Consecutive case series. Methods This study included patients with or without macular disease. All patients were scanned using the new biometry device (IOLMaster 700), which allows a 1.0 mm central retinal scan using SS-OCT technology. Also, all eyes were assessed using a dedicated retinal OCT device (RTVue) on the same day. Two experienced examiners and 1 ophthalmology resident graded all scans individually. Sensitivity and specificity for ...

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    12. Orbital Metastasis From Breast Cancer without Significant Changes in CT Scan and MRI

      Orbital Metastasis From Breast Cancer without Significant Changes in CT Scan and MRI

      Dear Editor , Orbital metastasis infrequently occurs in breast cancer ( 1 ); however breast cancer is the most common cause of orbital metastasis ( 2 - 5 ), followed by lung, prostate, gastrointestinal tract, and skin (melanoma) cancers ( 6 , 7 ). Definite diagnosis of an orbital lesion includes an orbital biopsy (either FNA or open biopsy). However, in patients with known metastatic cancer, CT scan or MRI of the orbits can frequently show the presence of a mass, which often involves the orbital fat or extraocular muscles ( 4 , 5 ). On the other hand, these techniques may not completely reflect the metastases. Optical coherence tomography (OCT) is ...

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    13. Optical coherence tomography in oral cancer: A transpiring domain

      Optical coherence tomography in oral cancer: A transpiring domain

      Identification of oral cancer at an early curable stage not only aids in controlling the mortality and morbidity rate but also improves the quality of life of the patient. Indeed, regular monitoring of such life-threatening disease has held an imperative role in cancer diagnostics. Various light-based diagnostics are currently available to the clinician for early diagnosis of oral cancer. Optical coherence tomography (OCT) is one such emerging light-based diagnostic modality that provides noninvasive, real-time images at a depth of 1.5–2 mm and can also be compared to corresponding histopathological sections, hence this procedure can also be referred as ...

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    14. Imaging Extracellular Matrix Remodeling In Vitro by Diffusion-Sensitive Optical Coherence Tomography

      Imaging Extracellular Matrix Remodeling In Vitro by Diffusion-Sensitive Optical Coherence Tomography

      The mammary gland extracellular matrix (ECM) is comprised of biopolymers, primarily collagen I, that are created and maintained by stromal fibroblasts. ECM remodeling by fibroblasts results in changes in ECM fiber spacing (pores) that have been shown to play a critical role in the aggressiveness of breast cancer. However, minimally invasive methods to measure the spatial distribution of ECM pore areas within tissues and in vitro 3D culture models are currently lacking. We introduce diffusion-sensitive optical coherence tomography (DS-OCT) to image the nanoscale porosity of ECM by sensing weakly constrained diffusion of gold nanorods (GNRs). DS-OCT combines the principles of ...

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  2. Organizations in the News

    1. (2 articles) Harvard University
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    1. (1 articles) Zeiss Stratus OCT
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  6. Picture Gallery

    Abbott Agrees to Buy St. Jude in $25 Billion Deal Hybrid intravascular imaging: recent advances, technical considerations, and current applications in the study of plaque pathophysiology Mount Sinai Health System Experts Share Skin Cancer Tips and Patient Stories for Skin Cancer Awareness Month and Melanoma Monday Automated analysis of multimodal fluorescence lifetime imaging and optical coherence tomography data for the diagnosis of oral cancer in the hamster cheek pouch model Three-dimensional morphological response of lipid-rich coronary plaques to statin therapy: a serial optical coherence tomography study Novel microscope-integrated stereoscopic heads-up display for intrasurgical optical coherence tomography OCT Angiography: Technology and Applications Webcast April 26th 2016, 1:00 EST 4D imaging of cardiac trabeculae contracting in vitro using gated OCT Post-doctoral Associate Position in Biophotonics/Biomedical Optical Imaging at Lehigh University Scalable wide-field optical coherence tomography-based angiography for in vivo imaging applications OCT in Central Nervous System Disease: The Eye as a Window to the Brain (Textbook) Michael Jenkins Wins American Association of Anatomists (AAA) Young Investigator Award
  7. Recent Quotes

    1. The real advantage of en face OCT is the ability to slice and dice the images throughout their entire depth, from the choroid to the vitreous.
      By Philip J. Rosenfeld
    2. En face OCT imaging became clinically useful with the advent of high-speed, high-density, spectral domain OCT raster-scanning techniques.
      By Philip J. Rosenfeld
    3. Our goal with MicroAngio is to provide a flexible tool that can be used in an optimal fashion for a wide range of applications...MicroAngio comes with customized probes and fixtures for small animal retinal, dorsal window chamber and brain imaging. We also provide a suite of algorithms for data analysis essential for angiographic imaging.”
      By Nishant Mohan
    4. In the majority of cases it is clinically and dermoscopically possible to differentiate between AK and BCC, but there are difficult situations, especially in early cases or during topical therapy, where the diagnosis, grading, subtype and/or lesion thickness is unclear...This data published shows that VivoSight OCT is not only able to differentiate between the two diseases by means of epidermal thickness and signal intensity measurements but also able to be used as a non-invasive technique to determine and monitor the treatment. This technology significantly improves the diagnostic methods currently used resulting in better outcomes for patients.
      By Julia Welzel
    5. We are thrilled to announce FDA clearance of our AngioVue System, which will bring the significant benefits of our innovative, non-invasive retinal imaging to patients in the U.S. who suffer from retinal diseases that lead to progressive blindness...Since we first introduced this technology to markets outside the U.S. fourteen months ago, the technology is in daily clinical use at over 525 clinical sites where it provides a more patient-friendly approach to diseases of the retina that lead to progressive blindness.
      By Jay Wei
    6. In the field of OCT imaging and biometry, size, price and operating power are three critical elements to commercialization in mass market applications...Our MRO system is the first version of OCT with the size, cost and operating power profile to address high volume applications in areas such as mobile personal health monitoring and biometric security.
      By Don Bogue
    7. The clinical benefit to the patient and the work flow to clinics have been a major impact to society.
      By Jay Wei
    8. OCT is a big saver of healthcare dollars – the guidance of anti-vascular endothelial growth factor therapy in age-related macular degeneration alone saves billions of dollars per year by avoiding unnecessary injections.
      By David Huang
    9. “Now we’re at a precipice of potentially a new frontier...This technology means that retina doctors are “seeing things we never thought we would see” and “seeing things maybe we don’t even know how to interpret.
      By Peter K. Kaiser
    10. This is a newsworthy application for those working in the ICU..."Infection is an ever-present risk, and an easier way to check for biofilm could see such checks done more often and infection rates lowered, which would be a great outcome.
      By David D. Sampson